Since this smart tag shows up when you paste an item, presumably in code, use the PasteSpecial method instead.

Now if you're talking about having code execute when you manually paste something in to the sheet this could be done via a Worksheet_Change event but I think you would find it problematic trying to figure out when it should and when it shouldn't convert the value.

Sub Converter()
Dim Cell As Range
For Each Cell In Selection
Cell.Formula = Cell.Formula
Next
End Sub

Befor execution of the Macro select the range you want to convert. The selection can contain Text, Dates, Formulas, ect. the Macro should only change numbers as text to regular numbers. One warning, do not include any cells with array formulas, the Macro will covert the array formulas to standard formulas.